<p>Reducing the dimensions and extending the service life of a pressure regulator intended for decrease of fluid pressure even when the pressure regulator operates with fluids such as high-pressure gas with corrosive properties. A pressure regulator comprising: a housing 2 having an inlet opening 21 for the supply of pressurized fluid under primary pressure from a pressurized fluid source and an outlet opening 22 for discharging the pressurized fluid under a secondary reduced pressure, and a channel between the aforementioned inlet opening 21 and outlet opening 22; and a pressure-regulating mechanism for reducing the aforementioned primary pressure to the aforementioned secondary pressure; the pressure regulator being characterized by the fact that the pressure-regulating mechanism has a moveable body 7 that comprises a diaphragm 8 which is displaceable in response to pressure fluctuations, the inlet opening 21 and the moveable body 7 being in line with each other in the direction substantially perpendicular to the direction of the diaphragm displacement.</p>
